Every year numerous fatalities and serious injuries occur in the construction and building industry as a result of workers using many of the scaffolding systems that are widely available today. In particular, many workers are injured or killed when they fall during assembly of the scaffold. In addition to the issue of worker safety, the cost to businesses, and particularly small to mid-size contractors in the industry, of the significant safety deficiencies of many commonly used scaffolding systems is substantial.
Despite these safety issues, the need for some type of scaffolding systems is undeniable. As the working level of a structure rises above the reach of crew members on the ground, scaffolding systems, which are essentially temporary elevated platforms, are erected to support the crew members, their tools, and materials. Building construction and repair require scaffold both for internal use as well as for external use in order to permit workers to stand at an elevation above ground surface to do work on areas of a building that is not accessible otherwise. For instance, a scaffold system is utilized in the installation of aluminum siding, or applying a coat of paint on the exterior of buildings.
There are many different types of scaffold systems in use today. For example, two general types of scaffold in use are suspended scaffolds and supported scaffolds. Suspended scaffolds are platforms suspended by ropes, or other non-rigid means, from an overhead structure. Many of the fatalities and injuries due to workers falling, associated with scaffold systems in general, are due to suspended scaffolds in particular.
In general, simple frame scaffolds are structurally safer and more efficient than suspended scaffolds. Supported scaffolds generally include one or more platforms supported by outrigger beams, brackets, poles, legs, uprights, posts, frames, or similar rigid support. Supported scaffolds comprise frame or fabricated, mobile, tube and coupler and pole scaffolds. Supported scaffold systems range from simple frame scaffolds to highly complex systems which may incorporate a motorized lift system.
Where complex support scaffold systems would be cost prohibitive for small and mid-sized contractors, a simple frame scaffold is desirable. Fabricated frame scaffolds, for example, are perhaps the most common type of scaffold because they are versatile, economical, and easy to use. They are frequently used in one or two tiers by residential contractors or small commercial and office contractors. However, frame scaffolds are often difficult and time-consuming to erect, largely because of their reliance on manual assembly. As such, they also place workers at substantial risk, particularly during assembly.
Manual assembly commonly requires individual hanger brackets to be lifted off of supports on the frame scaffold by a worker and moved up to another set of supports. This requires the heavy wood planks on top of the hangers to be removed or lifted so the bracket may be removed and placed in a new position. This exposes several workers to either crushing injuries or falls. The crushing injury often results from the planks slamming down on the bracket or falling completely from the scaffold. A fall typically occurs when a worker goes off balance while moving the hanger bracket or planks.
Further, the individual hanger brackets are spaced approximately three feet apart, so the brackets may only be moved in 3-foot increments. This is highly restrictive. Workers are typically forced to improvise as the structure approaches a ceiling or soffit of a building or other overhead obstruction that presents an obstacle to raising the boards. This compromises efficiency, productivity and worker safety.
Various other forms of scaffolding are also problematic. For example, a ladder jack scaffold is a simple device consisting of a platform resting on brackets attached to a ladder. Ladder jacks are limited to very light applications. Tube and coupler scaffolds are so-named because they are built from tubing connected by coupling devices, such scaffold systems are cost-prohibitive for small construction companies. Due to their strength, they are frequently used where heavy loads need to be carried, or where multiple platforms must reach several stories high. Their versatility, which enables them to be assembled in multiple directions in a variety of settings, also makes them hard to build correctly. Pole scaffolds are a type of supported scaffold in which every structural component, from uprights to braces to platforms, is made of wood.
Mobile scaffolds are a type of supported scaffold set on wheels or casters, they are designed to be easily moved and are commonly used in jobs like painting and plastering, where workers must frequently change positions. The brackets are designed to be raised and lowered in a manner similar to an automobile jack. However, mobile scaffolds are restricted to low levels and thus are very limited in usefulness.
Pump jack systems represent an alternative to some of the scaffold systems described above. The pump jacks typically include support arms that hold planks on which the workers can stand on when moving up and down along the pump jack poles. FIG. 1 is an illustration of a scaffold system that utilizes pump jacks in which pump jack poles are anchored on the ground by pole anchors and attached to the wall of the structure that the work is being done on, by pump jack braces for support. Pump jacks are operated to move up and down the pump jack poles to the desired height. The worker raises the pump jacks up with the foot, and lowers it by hand-cranking it down with a handle. A platform, e.g. a plank is supported between the jacks, and its height is adjusted by pumping the jacks and hand-cranking a handle. For example, one such scaffold that has been previously disclosed in the literature is depicted in FIG. 1, which is provided merely for comparison. As shown in the Figure, the pump jack system is physically attached to the wall of a structure (other than a scaffold structure itself, and has pump jack poles that are 30 feet or lower in height.
Thus, current pump jack systems are restricted to certain applications because they must be secured to a wall or other structure for support. Moreover, pump jacks cannot be used by heavy contractors because they lack material storage capability. Pump jack systems only provide support for workers and some miscellaneous small tools. They also lack guardrails or fall protection for the workers. Therefore, the pump jack systems are highly limited in their usefulness.
Accordingly, most of the previously available systems which are in wide use today are deficient in terms of safety, efficiency, affordability or some combination thereof. Therefore, it would be highly desirable to have a scaffold system that remedies these deficiencies. In particular, it would be desirable to have a scaffold system that cost effectively mechanizes the process of assembling frame scaffolding, instead of relying upon inefficient and dangerous manual assembly. Further, it would be highly desirable to have a scaffold system that is not limited to movement of the brackets in three foot increments, but instead allows unlimited movement to maximize flexibility and easily allow the scaffolding to be adapted to any overhead environment.
The present inventions overcomes the deficiencies of previously disclosed scaffolding systems, by providing independently-supported scaffold system that allow a wide variety of uses, and by extending the height of the pump jack poles for the purposes of utilizing such a scaffold system in a variety of structures, the present invention also overcomes the cost associated in setting up large scaffold systems, the safety issues associated with suspended scaffolds, the inefficient, and time-consuming manner required to securing the scaffold system to a structure. The present invention provides all of the benefits of previously available systems without comprising on safety. Further, this is accomplished by the present invention in a simple, cost-effective manner as required by small and mid-sized contractors. Moreover, the present invention provides a more efficient system that allows for faster assembly and disassembly of the scaffolding.